462 LETTERS TO DARWIN, 1843-1859 
Epoch ? Jukes, ^ I find, speculates in his sketch on Australia 
being two groups of islands ; was your review on Water- 
house anterior to this ? ^ 
Highlands of Abyssinia will not help you to connect the 
Cape and Austrahan temperate Floras ; they want all the 
types common to both and, worse than that, India notably 
wants them. Proteaceae, Thymeleaceae, Haempdoraceae, 
Acacia, Rutaceae of closely aUied genera (and in some cases 
species) are jammed up in S.W. Austraha and C.B.I. [Central 
British India] ; add to this EjMcrideae (which are mere § of 
Ericeae), and the absence or rarity of Rosaceae, &c., &c., &c., 
and you have an amount of similarity in the Floras, and 
dissimilarity to that of Abyssinia and India in the same 
features that does demand an explanation in any theoretical 
history of Southern vegetation. 
I still hold to a large Southern Continent characterised 
by these and the Antarctic types. Perhaps during the 
Cretaceous and Oohtic periods some of these types existed in 
the N. Hemisphere also ; — hence the Araucaria cones in 
Oolite, Banhsia wood of the sands at Chobham (what age 
are they ?) and cretaceous fossils supposed to be Proteaceae 
in Belgium, &c. ??? 
Are the coal and sandstone fossils of Australia Palaeozoic ? 
and is there in Austraha a gap in the Geolog. series between 
these and modern tertiary beds ? 
I also still regard plant types as older things than animal 
types. I have a fossil Araucaria cone from the Oolite iden- 
tical to all appearance with A. excelsa of Norfolk Island, 
and the Chobham fossil Banksia wood is identical with 
Tasmanian. I do not suppose specifically in either case, 
but that such highly organised types should be so similar, 
indicates a great age for them as types. 
[For Darwin's answer, dated Dec. 24, see CD. ii. 142.] 
^ Joseph Beete Jukes (1811-69), an admirable field geologist and writer, a 
pupil of Sedgwick, did pioneer geological work in NeT\ioundland, 1839-40, and 
spent four years on H.M.S. Fly as naturalist to the expedition which surveyed 
N.E. Austraha. Keturning to England in 1846, he joined the Geological Survey, 
and in 1850 became Director of the Irish Survey. His book referred to ia the 
text is A Sketch of the Physical Structure of Australia, 1850. 
^ In this unsigned review of A Natural History of the Mammalia, by G. R. 
Waterhousc, vol. i., in the Annals and Magazine of Nat. Hist., vol. xix., 1847, 
pp. 53-56, Darwin had speculated on the S.E. and S.W. corners of Australia 
having existed as two large islands, and only recently been joined. (M.L. i. 
448.) 
